I have not used it yet myself, but am researching it for ny 56 dodge peoject. One thing that impressed me about the Dynomat brand is when I bought a 4 speed setup for my wife's Corvette the guy was putting together an AMX it was a bare painted shell covered inside with Dynomat .... I stuck my head in the window and it was like entering the "cone of silence" unbelievable how the ambient noise vanished.
Itay be the most expensive option but it defiantly works so it is worth looking into The Dynomat brand.
Scott